Andy Roddick's tennis career will close at the U.S. Open, the site of his biggest triumph.

The 2003 champion at Flushing Meadows and former No. 1-ranked player decided to walk away from the sport whenever his U.S. Open ends, making the surprise announcement at a news conference Thursday, his 30th birthday.

"I'll make this short and sweet: I've decided that this is going to be my last tournament," said Roddick, wearing a black T-shirt and baseball cap.

"I just feel like it's time. I don't know that I'm healthy enough or committed enough to go another year," he said. "I've always wanted to, in a perfect world, finish at this event."

The 20th-seeded Roddick is scheduled to play Bernard Tomic of Australia in the second round Friday at Arthur Ashe Stadium.

"I think I wanted an opportunity to say goodbye to people, as well. I don't know how tomorrow's going to go, and I hope it goes well, and I'm sticking around," he said.

He was, by turns, in reflective and joking moods while speaking about his decision.

"If I do run into some emotions tomorrow or in four days, I don't want people to think I'm a little unstable. Or more unstable," Roddick said with a chuckle. "So that's why I came to this decision."

His title in New York nine years ago was the last time an American man won a Grand Slam singles title, and Roddick spoke wistfully about coming to the U.S. Open with his parents when he was 8.

He said he's "been thinking about (retirement) for a little bit," and knew for sure that the time is now after his 6-3, 6-4, 6-4 first-round victory over 21-year-old American Rhyne Williams.

"I've thought all year that I would know when I got to this tournament," he said, "and when I played the first round, I knew."